Surfaces in contact with marine environments (which include fresh water, brackish water and salt water environments) are known to become fouled by various types of organisms, both microorganisms and macro organisms. Vulnerable surfaces include, for example, the hulls of ships or the inside of pipes in circulating or pass-through water systems. Attaching themselves to these surfaces, organisms not only impede water flow across the surface hampering performance, but can also cause deterioration of the surface itself. As one example, Zebra mussels, which have relatively recently entered the Great Lakes, have been known to accumulate on and foul ship hulls and the water intake systems of power plants. Removing Zebra mussels takes ships or plant equipment out of service causing costly delays, repair, and cleanup. A need exists, therefore, for chemicals which combat biofouling and alleviate its adverse economic costs. Safety concerns, however, require that any such chemical should not pose undue harm to the environment or humans.
U.S. Pat. No. 5,384,176 describes the use of zosteric acid (p-sulfoxycinnamic acid) to control biofouling on surfaces in contact with marine environments. Zosteric acid is reported not only to be effective in combating biofouling but also to be environmentally safe. Zosteric acid occurs naturally in eelgrass Zostera marina. U.S. Pat. No. 5,384,176 discloses a method for isolating zosteric acid from methanolic extracts of eelgrass.
Extracting zosteric acid from eelgrass, however, can often be an expensive, time consuming processes with varying yields. If zosteric acid is to be a viable chemical to combat biofouling, there needs to be a synthetic route for its preparation and purification. The present invention answers that need by providing methods for the preparation of zosteric acid and its precursor, p-coumaric acid. The present invention also provides a method for purifying zosteric acid. These processes supply zosteric acid in good yield and high purity.